Walkclj is a complimentary library to parseclj and parseedn. These Clojure/EDN parsing libraries return a parse tree, this library lets you navigate that parse tree as if it was a regular clojure/edn data structure.

For example when parsing (foo bar) you get

(setq parse-tree
      ;; (parseclj-parse-clojure "(foo bar)")
      '((:node-type . :root)
        (:position . 1)
        (:children ((:node-type . :list)
                    (:position . 1)
                    (:children ((:node-type . :symbol)
                                (:position . 2)
                                (:form . "foo")
                                (:value . foo))
                               ((:node-type . :symbol)
                                (:position . 6)
                                (:form . "bar")
                                (:value . bar)))))))

;; There's an extra wrapping because parseclj accepts multiple top-level forms

(walkclj-ffirst parse-tree)
;;=> ((:node-type . :symbol) (:position . 2) (:form . "foo") (:value . foo))

(walkclj-list-p (walkclj-first parse-tree)) ;;=> t

(walkclj-name (walkclj-ffirst parse-tree)) ;;=>"foo"

We currently implement the following functions, all match their Clojure equivalent:

• (walkclj-ffirst form)
• (walkclj-first form)
• (walkclj-list-p form)
• (walkclj-meta form)
• (walkclj-name form)
• (walkclj-second form)
• (walkclj-symbol-p form)

There's a macro walkclj-do which lets you omit the walkclj- prefix, and also allows writing Clojure-style keyword lookups:

(macroexpand-1 '
 (walkclj-do
  (:foo (list? (first parse-tree))))) 
;; => (a-get (walkclj-list-p (walkclj-first parse-tree)) :foo)

Two special helpers:

• (walkclj-unwrap-meta form): Optionally unwrap a :meta type parse node. Any Clojure literal that has metadata will get an extra wrapper in the parse tree, this unwraps that, if it's there.

• (walkclj-current-ns): Get the namespace name of the current buffer, assumes the first form in the buffer is an ns form

Patches are welcome! Any function that mimics a clojure.core function is fair game.

Copyright © 2018-2022 Arne Brasseur and Contributors

Licensed under the term of the GNU General Public License, version 3.